The present invention relates to communication networks, and, more particularly, to communication networks that support vehicle communication.
Automotive driver assist features in cars are becoming commonplace. Automotive manufacturers are using automation to assist with vehicle safety and routing. Many organizations—both governmental and commercial—are working on new technologies that may enable greater safety and efficiency in automotive transportation. As driving becomes more automated, some research predict that at least 80% of all accidents can be avoided, carbon emissions reduced substantially, and more effective use of road and parking space can be achieved.
Vehicle-to-vehicle communication technology is currently provided on some cars and may be widespread in the future. Vehicle-to-infrastructure communication technology is being developed and tested and is also expected to become widespread in the future.
The IEEE 802.11p industry standard has been developed to support vehicle-to-infrastructure communication and many governmental authorities and regulatory bodies around the world have allocated frequencies near 5 GHz for vehicular communications. With the cars available now that can talk to each other, vehicle-to-infrastructure is expected to be deployed in more areas to improve vehicular safety and driver convenience.
FIG. 1 illustrates a conventional vehicle-to-infrastructure system in which a roadside unit is used to provide connectivity support to passing vehicles. As shown in FIG. 1, a roadside unit (RSU) 110 is used to communicate with vehicles near an intersection, such as vehicle 120, to provide each other with information, such as safety warnings and traffic information. The RSU 110 and the communication unit in the vehicle 120 are both dedicated short-range communications (DSRC) devices. DSRC works in the 5.9 GHz band with a bandwidth of 75 MHz and an approximate range of 1000 meters. The communication between nodes comprising vehicles and roadside units may be part of an overall intelligent transportation system (ITS).
Operation of vehicle-to-infrastructure communication may be illustrated by way of example with reference to FIG. 1. In the scenario illustrated in FIG. 1, a traffic signal controller 130 transfers information to the RSU 110 regarding the signal phase of the traffic light 140 and the amount of time remaining until the light changes. The RSU 110 transmits the traffic light 140 information to the vehicle 120. The on-board communication unit in the vehicle 120 receives the RSU 110 information and displays an appropriate alert regarding the state of the traffic signal 140 for the driver. For example, the vehicle may provide a visual and/or auditory alert that the driver is at risk of running a red light. A backhaul connection 150, such as a fiber optic and/or electrical cable may be used to connect a traffic management center 160 to the traffic signal controller 130 and/or the RSU 110. The traffic management center 160 may manage the flow of traffic on surrounding roads and highways based on data collected from vehicles and RSUs, such as the vehicle 120 and the RSU 110.